Crude oil generally refers to a complex mixture of hydrocarbons which is obtained from geological formations beneath the earth, and from which refined petroleum products can be obtained through fractional distillation. Fractional distillation in a refinery is a multi-step process. Each step in the process yields different products in the form of distillates and residues at different boiling ranges. Crude oils vary considerably from each other in yields of these products and in properties of the yields obtained. A detailed analysis of crude oil characteristics, such as probable yields, blends, pricing, processability, hydrogen consumption in hydro processing, quality, residue-potential, and the like, is used for the purpose of making business decisions, and for planning, controlling and optimization of refinery operations. Such characteristics of a crude oil will be herein referred to as refining characteristics.
The refining characteristics help not only in taking business decisions for a crude oil sample, but are also a source for meeting refinery constraints, product demand and specifications, predicting distillates and residue yields, predicting processing costs, routing of intermediate distillate streams for maximum profits, and hydrogen management.
The conventional methods for evaluating the refining characteristics of crude oils either involve laboratory distillation of an oil sample or detailed molecular and spectroscopic analysis based on, for example, Nuclear magnetic resonance (NMR) spectroscopy, Gas Chromatography-Mass Spectroscopy (GC-MS), Infrared (IR) spectroscopy and Ultraviolet (UV) spectroscopy. The spectroscopic methods exploit the magnetic properties and the spectra of light for certain atomic nuclei to determine the chemical and physical properties of the sample in which they are contained.